66021187 has 2 divisors, whose sum is σ = 66021188. Its totient is φ = 66021186.

The previous prime is 66021173. The next prime is 66021239. The reversal of 66021187 is 78112066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66021187 - 2¹¹ = 66019139 is a prime.

It is not a weakly prime, because it can be changed into another prime (66021287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33010593 + 33010594.

It is an arithmetic number, because the mean of its divisors is an integer number (33010594).

Almost surely, 2^66021187 is an apocalyptic number.

66021187 is a deficient number, since it is larger than the sum of its proper divisors (1).

66021187 is an equidigital number, since it uses as much as digits as its factorization.

66021187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 66021187 is about 8125.3422697139. The cubic root of 66021187 is about 404.1672407450.

The spelling of 66021187 in words is "sixty-six million, twenty-one thousand, one hundred eighty-seven".